Display device capable of facilitating substrate bonding with alignment key and method of fabricating the same

ABSTRACT

A display device is provided. An embodiment of a display device includes a first substrate, a second substrate disposed on the first substrate, first and second partition walls disposed on the second substrate, the second partition wall being disposed outside the first partition wall, a first trench disposed inside the first partition wall and having a first width, a second trench disposed between the first and second partition walls and having a second width greater than the first width; an alignment key disposed to overlap the second trench; a first spacer disposed on the alignment key, and a sealing member disposed along an edge between the first substrate and the second substrate without overlapping the alignment key, wherein the first spacer partially overlaps the first partition wall, the second partition wall, and the sealing member.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2020-0075704 filed on Jun. 22, 2020, in the Korean IntellectualProperty Office, and all the benefits accruing therefrom under 35 U.S.C.119, the contents of which in its entirety are herein incorporated byreference.

BACKGROUND 1. Technical Field

Particularly, the present disclosure relates to a display device and amethod of fabricating the same. More particularly, the presentdisclosure relates to a display device capable of facilitating substratebonding with an alignment key and a method of fabricating the same.

2. Description of the Related Art

Recently, the importance of display devices has steadily increased withthe development of multimedia technology. Accordingly, various types ofdisplay devices such as a liquid crystal display (LCD), an organic lightemitting display (OLED) and the like have been used widely.

Among the display devices, a self-light emitting display device includesa self-light emitting element such as an organic light emitting diode.Generally, the self-light emitting element may include two oppositeelectrodes and a light emitting layer interposed therebetween. In thecase of using the organic light emitting diode as the self-lightemitting element, the electrons and holes from the two electrodes arerecombined in the light emitting layer to produce excitons, whichtransit from the excited state to the ground state, emitting light.

Such a self-light emitting display device is attracting attention as anext-generation display device because of being able to meet the highdisplay quality requirements such as wide viewing angle, high brightnessand contrast, and quick response speed as well as being able to be madehaving a low power consumption, lightweight, and thin due to nonecessity of a separate power source.

SUMMARY

Aspects of the present disclosure provide a display device capable offacilitating substrate bonding with an alignment key that is easilyvisible from a front surface of a substrate and a method of fabricatingthe display device.

However, aspects of the present disclosure are not restricted to the oneset forth herein. The above and other aspects of the present disclosurewill become more apparent to one of ordinary skill in the art to whichthe present disclosure pertains by referencing the detailed descriptionof the present disclosure given below.

An embodiment of a display device includes a first substrate; a secondsubstrate disposed on the first substrate; first and second partitionwalls disposed on the second substrate, the second partition wall beingdisposed outside the first partition wall; a first trench disposedinside the first partition wall and having a first width; a secondtrench disposed between the first and second partition walls and havinga second width greater than the first width; an alignment key disposedto overlap the second trench; a first spacer disposed on the alignmentkey; and a sealing member disposed along an edge between the firstsubstrate and the second substrate without overlapping the alignmentkey, wherein the first spacer partially overlaps the first partitionwall, the second partition wall, and the sealing member.

Another embodiment of a display device includes a second substratedisposed on the first substrate; a sealing member disposed along an edgeof the first substrate between the first substrate and the secondsubstrate; first and second partition walls disposed on the secondsubstrate, the second partition wall being disposed to surround thefirst partition wall; an alignment key disposed between the first andsecond partition walls without overlapping the sealing member; and afirst spacer disposed on the alignment key and partially overlapping thefirst partition wall and the second partition wall, wherein the sealingmember is disposed over the first spacer and the second partition wall.

An embodiment of a method of fabricating a display device includespreparing a first substrate and a second substrate in which a displayarea, a dummy area disposed to surround the display area, and a sealingarea disposed to surround the dummy area are defined; forming a firstpartition wall(s) in the dummy area of the second substrate, and forminga second partition wall in the sealing area of the second substrate;forming a first spacer in a trench defined by an outer side surface ofthe first partition wall, an upper surface of the second substrate, andan inner side surface of the second partition wall; disposing a sealingmember over the second partition wall and the first spacer, the sealingmember surrounding an edge of the second substrate; and bonding thefirst substrate to the second substrate, wherein the first spacerpartially overlaps the first partition wall and the second partitionwall.

According to the display device and the method of fabricating thedisplay device in accordance with an embodiment, it may include a trenchdisposed in a non-display area and having an alignment key arrangedtherein. A spacer may be disposed inside the trench to overlap thealignment key. The spacer may include a transparent material so that thealignment key is easily visualized from the front surface of thesubstrate, thereby facilitating substrate bonding.

The effects of the present disclosure are not limited to theaforementioned effects, and various other effects are included in thepresent specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present disclosure willbecome more apparent by describing in detail example embodiments thereofwith reference to the attached drawings, in which:

FIG. 1 is a perspective view of a display device according to anembodiment;

FIG. 2 is a cross-sectional view taken along line II-IT of FIG. 1 ;

FIG. 3 is a plan view illustrating a part of the display device of FIG.1 ;

FIG. 4 is a partial cross-sectional view of the display area of FIG. 3 ;

FIG. 5 is a cross-sectional view taken along line V-V′ of FIG. 3 ;

FIGS. 6, 7, 8, 9, 10, and 11 are schematic views illustrating a methodof fabricating a display device according to an embodiment;

FIG. 12 is a plan view of a display device according to anotherembodiment;

FIG. 13 is a cross-sectional view taken along line XIV-XIV′ of FIG. 12 ;

FIG. 14 is a plan view of a display device according to still anotherembodiment;

FIG. 15 is a cross-sectional view taken along line XV-XV′ of FIG. 14 ;and

FIG. 16 is a cross-sectional view of a display device according to stillanother embodiment.

DETAILED DESCRIPTION

The present disclosure will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the disclosure are shown. This disclosure may, however, be embodiedin different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the disclosure to those skilled in the art.

It will also be understood that when a layer is referred to as being“on” another layer or substrate, it can be directly on the other layeror substrate, or intervening layers may also be present. In contrast,when an element is referred to as being “directly on” another element,there are no intervening elements present.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the example term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The same reference numbers indicate the same components throughout thespecification.

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings.

FIG. 1 is a perspective view of a display device according to anembodiment.

Referring to FIG. 1 , a display device 1 may refer to any electronicdevice providing a display screen. Examples of the display device 1 mayinclude a television, a laptop computer, a monitor, a billboard, amobile phone, a smartphone, a tablet personal computer (PC), anelectronic watch, a smart watch, a watch phone, a mobile communicationterminal, an electronic notebook, an electronic book, a portablemultimedia player (PMP), a navigation device, a game machine, a digitalcamera, an Internet-of-Things device and the like, which provide adisplay screen.

The display device 1 illustrated in the drawing is a television (TV).The display device 1 may have a high resolution or an ultra highresolution such as HD, UHD, 4K, and 8K, without being limited thereto.

The display device 1 may have a rectangular shape in a plan view. Theplanar shape of the display device 1 is not limited to the exemplifiedone, but may have a circular shape or other shapes.

The display device 1 may include a display area DA displaying an imageand a non-display area NDA not displaying an image. The display area DAmay include a plurality of pixels PX. The non-display area NDA may belocated around the display area DA and may surround the display area DA.Details of the display area DA and the non-display area NDA will bedescribed later with reference to FIGS. 3, 4, and 5 .

FIG. 2 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1 .

Referring to FIG. 2 , the display device 1 may include a first substrate10 and a second substrate 20 facing the first substrate 10. The displaydevice 1 may further include a sealing member 50 that bonds the firstsubstrate 10 to the second substrate 20, and a filling layer 70 filledbetween the first substrate 10 and the second substrate 20.

The first substrate 10 may include elements and circuits for displayingan image, for example, a pixel circuit such as a switching element, apixel defining layer PDL (see FIG. 4 ) that defines an emission regionand a non-emission region, and a self-light emitting element. In anexample embodiment, the self-light emitting element may include at leastone of an organic light emitting diode, a quantum dot light emittingdiode, an inorganic micro light emitting diode (e.g., micro LED), or aninorganic nano light emitting diode (e.g., nano LED). Hereinafter, acase where the self-light emitting element is an organic light emittingdiode will be described by way of example.

The second substrate 20 may be disposed on the first substrate 10 andmay face the first substrate 10. The second substrate 20 may include acolor control structure that converts the color of incident light. Thecolor control structure may control the wavelength of incident light,thereby converting the color of incident light.

The sealing member 50 may be positioned between the first substrate 10and the second substrate 20 in the non-display area NDA. The sealingmember 50 may be disposed along the edges of the first substrate 10 andthe second substrate 20 in the non-display area NDA, and may surroundthe display area DA in a plan view.

The filling layer 70 may be disposed in a space between the firstsubstrate 10 and the second substrate 20 surrounded by the sealingmember 50. The filling layer 70 may fill the space between the firstsubstrate 10 and the second substrate 20.

FIG. 3 is a plan view illustrating a part of the display device of FIG.1 . FIG. 4 is a partial cross-sectional view of the display area of FIG.3 . FIG. 5 is a cross-sectional view taken along line V-V′ of FIG. 3 .FIG. 5 is a cross-sectional view of a part of a dummy area and a sealingarea of a display device.

Referring to FIGS. 3, 4, and 5 , the display area DA and the non-displayarea NDA may be defined in the display device 1 as described above. Thedisplay area DA may include a plurality of pixels PX and substantiallycontribute to image display. As used herein, the term “pixel” may mean asingle area defined by dividing the display area DA for image display orcolor display in a plan view, and one pixel may display a predeterminedbase color. That is, one pixel may be a minimum unit area capable ofdisplaying a color independently of the other pixels. Examples of thebase color may include red, green, and blue, but the present disclosureis not limited thereto.

Each of the plurality of pixels PX may display different colors. In anexample embodiment, the plurality of pixels PX may include a first pixeldisplaying a first color, a second pixel displaying a second colorhaving a peak wavelength shorter than the first color, and a third pixeldisplaying a third color having a peak wavelength shorter than thesecond color. The first, second, and third pixels may form one repeatingunit, and the repeating unit may be repeatedly arranged in a firstdirection DR1. Each of the first to third pixels may also be repeated ina second direction DR2, so that the plurality of pixels PX may bearranged in a matrix in a plan view.

The non-display area NDA may be disposed around the display area DA. Thenon-display area NDA may completely or partially surround the displayarea DA. The non-display area NDA may not contribute to image displayunlike the display area DA. The non-display area NDA may form a bezel ofthe display device 1. In the non-display area NDA, components (e.g., aconnection pad, a driving circuit, etc.) required for driving thedisplay device 1 may be disposed.

The non-display area NDA may include a sealing area SA where the sealingmember 50 is disposed and a dummy area DMA which is positioned on theinside (i.e., on the display area DA side) in comparison with thesealing area SA. The display area DA may be surrounded by the dummy areaDMA. Further, the dummy area DMA may be surrounded by the sealing areaSA.

The dummy area DMA may include a plurality of dummy pixels DX. The dummypixels DX disposed in the dummy area DMA do not contribute to imagedisplay, but may include dummy pixel electrodes PXEd.

In the display area DA, the display device 1 may include a first basesubstrate 11, a pixel electrode PXE disposed for each pixel PX of thefirst base substrate 11, a pixel defining layer PDL disposed along theboundaries of the pixels PX of the first base substrate 11, a lightemitting layer EML disposed on the pixel electrode PXE in an openingexposed by the pixel defining layer PDL, a common electrode CME disposedon the light emitting layer EML and the pixel defining layer PDL acrossthe plurality of pixels PX, and an encapsulation structure ECL disposedon the common electrode CME.

The pixel defining layer PDL may overlap an edge portion of the pixelelectrode PXE. The light emitting layer EML may include an organic lightemitting material. The organic light emitting material of the lightemitting layer EML may emit the same color regardless of the color pixelPX. For example, the light emitting layer EML may emit blue light fromall of the red, green, and blue pixels PX. However, the embodiment ofthe present disclosure is not limited thereto. The pixel defining layerPDL may include the openings exposing the pixel electrodes PXE. Thepixel defining layer PDL may be disposed on the first base substrate 11across the display area DA and the dummy area DMA which will bedescribed later, but is not limited thereto.

The encapsulation structure ECL may include at least one thin filmencapsulation layer. The encapsulation structure ECL may be entirelydisposed above the first base substrate 11 over the display area DA, andthe dummy area DMA and the sealing area SA which will be describedlater. The encapsulation structure ECL may function to protect membersdisposed on the first base substrate 11 against the externalenvironment. For example, the thin film encapsulation layer may includea first inorganic layer 17, an organic layer 18, and a second inorganiclayer 19. The first and second inorganic layers 17 and 19 may include aninsulating inorganic material, and the organic layer 18 may include aninsulating organic material.

In the display area DA, the second substrate 20 may include a secondbase substrate 21, a light blocking member BML disposed on one surfaceof the second base substrate 21, which faces the first base substrate11, a color filter layer CFL disposed on one surface of the second basesubstrate 21 in an opening defined by the light blocking member BML, afirst capping layer 22 disposed on the color filter layer CFL, a firstpartition wall PTL1 disposed on the first capping layer 22 to overlapthe light blocking member BML, a first trench TR1 that is defined as aspace surrounded by the first partition walls PTL1, a wavelengthconversion layer WCL and a light transmitting layer TPL disposed in thefirst trenches TR1, and a first spacer CS1 disposed on at least apartial area of the first partition wall PTL1. In addition, in thedisplay area DA, the second substrate 20 may further include a secondcapping layer 23 that covers the first partition wall PTL1, thewavelength conversion layer WCL, the light transmitting layer TPL, andthe first spacer CS1.

The light blocking member BML may be disposed in a light blocking areaBA to overlap the pixel defining layer PDL, and include the openingsthat expose one surface of the second base substrate 21 whileoverlapping light transmitting areas TA. The light blocking member BMLmay be disposed on the second base substrate 21 across the dummy areaDMA and the sealing area SA, which will be described later, as well asthe display area DA.

The color filter layer CFL may include a first color filter layer CFL1disposed in the first color pixel PX, a second color filter layer CFL2disposed in the second color pixel PX, and a third color filter layerCFL3 disposed in the third color pixel PX. For example, the first colorfilter layer CFL1 may be a red color filter layer, the second colorfilter layer CFL2 may be a green color filter layer, and the third colorfilter layer CFL3 may be a blue color filter layer.

The first capping layer 22 may cover the light blocking member BML andthe color filter layer CFL. The first capping layer 22 may be disposedabove the second base substrate 21 across the dummy area DMA and thesealing area SA, which will be described later, as well as the displayarea DA.

The first partition wall PTL1 may include the plurality of firsttrenches TR1 penetrating the first partition wall PTL1 in the thicknessdirection. The first trenches TR1 may be disposed to be spaced apartfrom each other. The first partition wall PTL1 may be integrally formedwith a second partition wall PTL2 which will be described later, but isnot limited thereto.

The wavelength conversion layer WCL may include a first wavelengthconversion pattern WCL1 disposed in the first color pixel PX and asecond wavelength conversion pattern WCL2 disposed in the second colorpixel PX. The light transmitting layer TPL may be disposed in the thirdcolor pixel PX.

The first wavelength conversion pattern WCL1 may include a first baseresin BRS1, and a first wavelength conversion material WCP1 andscatterers SCP provided in the first base resin BRS1. The secondwavelength conversion pattern WCL2 may include a second base resin BRS2,and a second wavelength conversion material WCP2 and scatterers SCPprovided in the second base resin BRS2. The light transmitting layer TPLmay include a third base resin BRS3 and scatterers SCP provided in thethird base resin BRS3.

The first, second, and third base resins BRS1, BRS2, and BRS3 mayinclude a light-transmitting organic material. For example, the first,second, and third base resins BRS1, BRS2, and BRS3 may include an epoxyresin, an acrylic resin, a cardo resin, an imide resin or the like. Thefirst, second, and third base resins BRS1, BRS2 and BRS3 may be formedof the same material, but the present disclosure is not limited thereto.

The scatterers SCP may be metal oxide particles or organic particles.Examples of the metal oxide may include titanium oxide (TiO₂), zirconiumoxide (ZrO₂), aluminum oxide (Al₂O₃), indium oxide (In₂O₃), zinc oxide(ZnO), tin oxide (SnO₂), and the like. Examples of a material of theorganic particles may include acrylic resin and urethane resin, and thelike.

The first wavelength conversion material WCP1 may convert the thirdcolor into the first color, and the second wavelength conversionmaterial WCP2 may convert the third color into the second color. Thefirst wavelength conversion material WCP1 and the second wavelengthconversion material WCP2 may be quantum dots, quantum bars, phosphors orthe like. Examples of the quantum dots may include group IVnanocrystals, group II-VI compound nanocrystals, group III-V compoundnanocrystals, group IV-VI nanocrystals, and combinations thereof. Thefirst wavelength conversion pattern WCL1 and the second wavelengthconversion pattern WCL2 may further include scatterers SCP forincreasing wavelength conversion efficiency.

The light transmitting layer TPL disposed in the third color pixel PXtransmits light of the third color emitted from the light emitting layerEML while maintaining the wavelength of the light. The scatterers SCP ofthe light transmitting layer TPL may serve to control an emission pathof the light emitted through the light transmitting layer TPL. The lighttransmitting layer TPL may not include a wavelength conversion material.

The first spacer CS1 may be disposed on the partial area of the firstpartition wall PTL1 and may also be disposed in the light blocking areaBA. The first spacer CS1 may serve to maintain the distance between thefirst substrate 10 and the second substrate 20 in the display area DA.The first spacer CS1 may be formed through an exposure and developmentprocess. For example, the first spacer CS1 may include an organicmaterial, and the organic material may be a photosensitive organicmaterial. In this case, the first spacer CS1 may be formed by applyingan organic material layer for spacers and then exposing and developingit. The organic material layer for spacers may be a negativephotosensitive material which is cured at a portion irradiated withlight, but is not limited thereto. The first spacer CS1 may be made of atransparent material.

The filling layer 70 may be disposed between the first substrate 10 andthe second substrate 20. The filling layer 70 may fill a space betweenthe first substrate 10 and the second substrate 20, and may serve tobond them to each other. The filling layer 70 may be disposed betweenthe encapsulation structure ECL of the first substrate 10 and the secondcapping layer 23 of the second substrate 20.

In the dummy area DMA, the first substrate 10 may include the first basesubstrate 11, the dummy pixel electrode PXEd disposed for each dummypixel DX of the first base substrate 11, the pixel defining layer PDLdisposed along the boundaries of the dummy pixels DX of the first basesubstrate 11, a dummy light emitting layer EMLd disposed on the dummypixel electrode PXEd in the opening exposed by the pixel defining layerPDL, the common electrode CME disposed on the dummy light emitting layerEMLd and the pixel defining layer PDL across the plurality of dummypixels DX, and the encapsulation structure ECL disposed on the commonelectrode CME. In the non-display area NDA, the dummy area DMA and thesealing area SA may be distinguished by an imaginary line perpendicularto the edge of the common electrode CME. For example, the dummy area DMAand the sealing area SA may be respectively disposed on one side and theother side with respect to the imaginary line perpendicular to the edgeof the common electrode CME.

Descriptions of the dummy pixel electrode PXEd, the pixel defining layerPDL, the dummy light emitting layer EMLd, and the common electrode CMEdisposed in the dummy area DMA are respectively the same as those of thepixel electrode PXE, the pixel defining layer PDL, the light emittinglayer EML and the common electrode CME disposed in the display area DA.In the dummy area DMA, the first substrate 10 may include all of thedummy pixel electrode PXEd, the pixel defining layer PDL, the dummylight emitting layer EMLd, and the common electrode CME, but is notlimited thereto and some of them may be omitted.

In the dummy area DMA, the second substrate 20 may include the secondbase substrate 21, the light blocking member BML disposed on one surfaceof the second base substrate 21, which faces the first base substrate11, a dummy color filter layer CFLd disposed on one surface of thesecond base substrate 21 in the opening defined by the light blockingmember BML, the first capping layer 22 disposed on the dummy colorfilter layer CFLd, the second partition wall PTL2 disposed on the firstcapping layer 22 to overlap the light blocking member BML, a secondtrench TR2 that is defined as a space surrounded by the second partitionwalls PTL2, a dummy wavelength conversion layer WCL1 d and WCL2 d, and adummy light transmitting layer TPLd disposed in the second trenches TR2,and a second spacer CS2 disposed on at least a part of the secondpartition wall PTL2. The second substrate 20 may further include thesecond capping layer 23 disposed on the dummy wavelength conversionlayer WCL1 d and WCL2 d, the dummy light transmitting layer TPLd, thesecond partition wall PTL2, and the second spacer CS2.

The light blocking member BML may be disposed in a light blocking areaBAd to overlap the pixel defining layer PDL, and include the openingsthat expose one surface of the second base substrate 21 whileoverlapping light transmitting areas TAd.

The dummy color filter layer CFLd may include a first dummy color filterlayer CFL1 d, a second dummy color filter layer CFL2 d, and a thirddummy color filter layer CFL3 d. Descriptions of the first to thirddummy color filter layers CFL1 d, CFL2 d, and CFL3 d are the same asthose of the first, second, and third color filter layers CFL1, CFL2,and CFL3 described above and thus will be omitted.

The second partition wall PTL2 may include the plurality of secondtrenches TR2 penetrating the second partition wall PTL2 in the thicknessdirection. The second trenches TR2 may be disposed to be spaced apartfrom each other. Each of the second trenches TR2 may have a first widthW1. As described above, the second partition wall PTL2 may be integrallyformed with the first partition wall PTL1, but is not limited thereto.The upper surface of the second partition wall PTL2 may be positioned onthe same plane as the upper surface of the first partition wall PTL1.

The dummy wavelength conversion layer WCL1 d and WCL2 d may include afirst dummy wavelength conversion pattern WCL1 d disposed in the firstcolor dummy pixel DX and a second dummy wavelength conversion patternWCL2 d disposed in the second color dummy pixel DX. The dummy lighttransmitting layer TPLd may be disposed in the third color dummy pixelDX.

Descriptions of the dummy wavelength conversion layer WCL1 d and WCL2 d,and the dummy light transmitting layer TPLd of the dummy area DMA arethe same as those of the wavelength conversion layer WCL and the lighttransmitting layer TPL of the display area DA described above and thuswill be omitted. In the dummy area DMA, the second substrate 20 mayinclude all of the light blocking member BML, the dummy color filterlayer CFLd, the second partition wall PTL2, the dummy wavelengthconversion layer WCL1 d and WCL2 d, the dummy light transmitting layerTPLd, and the second spacer CS2, but is not limited thereto and some ofthem may be omitted.

The second spacer CS2 may be disposed on the second partition wall PTL2and may also be disposed in the light blocking area BAd. The secondspacer CS2 may serve to maintain the distance between the firstsubstrate 10 and the second substrate 20 in the dummy area DMA. Otherdetails of the second spacer CS2 are the same as those of the firstspacer CS1 described above and thus will be omitted.

The sealing area SA may be disposed outside the dummy area DMA. In thesealing area SA, the first substrate 10 may include the first basesubstrate 11 and the encapsulation structure ECL disposed on the firstbase substrate 11. The encapsulation structure ECL disposed in thesealing area SA may include the first inorganic layer 17, the organiclayer 18, and the second inorganic layer 19, similarly to theencapsulation structures ECL disposed in the display area DA and thedummy area DMA.

In the sealing area SA, the second substrate 20 may include the secondbase substrate 21, the light blocking member BML disposed on one surfaceof the second base substrate 21, which faces the first base substrate11, the first capping layer 22 disposed on the light blocking memberBML, a third partition wall PTL3 disposed on the first capping layer 22to overlap the light blocking member BML, a third trench TR3 defined bythe outer side surface of the outermost second partition wall PTL2, theinner side surface of the third partition wall PTL3, and the uppersurface of the first capping layer 22, and a third spacer CS3 disposedin the third trench TR3. Further, in the sealing area SA, the secondsubstrate 20 may further include the second capping layer 23 whichcovers the third partition wall PTL3 and the third spacer CS3.

The display device 1 according to an embodiment may include the thirdtrench TR3 that is a space defined by the outer side surface of theoutermost second partition wall PTL2, the inner side surface of thethird partition wall PTL3, and the upper surface of the first cappinglayer 22. The third trench TR3 may be disposed in the non-display areaNDA. In one embodiment, the third trench TR3 may be disposed across thedummy area DMA and the sealing area SA, but is not limited thereto. Thethird trench TR3 may have a second width W2 greater than the first widthW1 of the second trench TR2.

The third trench TR3 may partially expose the first capping layer 22.The third spacer CS3 may be disposed in the third trench TR3. The thirdspacer CS3 may serve to maintain the distance between the firstsubstrate 10 and the second substrate 20 in the sealing area SA. Thethird spacer CS3 may be made of the same material as the first andsecond spacers CS1 and CS2, and may be formed together, but is notlimited thereto.

The third spacer CS3 may partially overlap the outermost secondpartition wall PTL2 and the third partition wall PTL3. The third spacerCS3 may be disposed to partially cover the upper surface of theoutermost second partition wall PTL2 and the upper surface of the thirdpartition wall PTL3. A flat region may be provided between a region ofthe third spacer CS3, which overlaps the outermost second partition wallPTL2, and a region of the third spacer CS3, which overlaps the thirdpartition wall PTL3. The regions of the third spacer CS3 overlapping theoutermost second partition wall PTL2 and the third partition wall PTL3may have protruding shapes in comparison to the flat region, but are notlimited thereto.

The display device 1 according to an embodiment may further include analignment key AK disposed inside the third trench TR3. The alignment keyAK may be disposed to align the first substrate 10 and the secondsubstrate 20 when bonding them. The alignment key AK may be arranged tooverlap the third trench TR3. The alignment key AK may include, forexample, an organic material or an inorganic material, but is notlimited thereto. The alignment key AK may be patterned in a cross shape,but is not limited thereto.

In the sealing area SA, the sealing member 50 may be disposed betweenthe first substrate 10 and the second substrate 20. The first substrate10 and the second substrate 20 may be bonded to each other via thesealing member 50. The sealing member 50 may include an organicmaterial. The sealing member 50 may be made of an epoxy resin, but isnot limited thereto. The sealing member 50 may be disposed over thethird spacer CS3 and the third partition wall PTL3. The sealing member50 may partially overlap the third spacer CS3 and the third partitionwall PTL3. The sealing member 50 may be disposed outside the alignmentkey AK without overlapping the alignment key AK. The filling layer 70may be disposed inside the sealing member 50.

In the display device 1 according to an embodiment, the dummy area DMAincluding the dummy pixels DX may be disposed outside the display areaDA in order to prevent the display quality of the display device 1 frombeing deteriorated due to a residue phenomenon occurring in a spacebetween the first partition walls PTL1 in the display area DA.

Further, the second substrate 20 may include the alignment key AK toalign the first substrate 10 and the second substrate 20 when bondingthem. When the alignment key AK is disposed in the dummy area DMA, itmay be difficult to visually recognize the alignment key AK from thefront surface of the second substrate 20 due to the dummy pixels DX.

The second substrate 20 included in the display device 1 according to anembodiment may have the third trench TR3 disposed in the non-displayarea NDA, and the alignment key AK may be disposed in the third trenchTR3. Further, the third spacer CS3 may be arranged in the third trenchTR3 to overlap the alignment key AK. The third spacer CS3 may include atransparent material so that the alignment key AK can be easilyvisualized from the front surface of the second substrate 20.

Hereinafter, a method of fabricating the display device 1 will bedescribed.

FIGS. 6, 7, 8, 9, 10, and 11 are schematic views illustrating a methodof fabricating a display device according to an embodiment. FIGS. 6, 7,8, 9, 10, and 11 illustrate the non-display area NDA in the fabricatingprocess of the second substrate 20. FIGS. 6, 7, 8, 9, 10, and 11illustrate the second substrate 20 of FIGS. 4 and 5 in an upside-downstate for convenience of description.

Referring to FIG. 6 , light blocking members BML are formed on onesurface of the second base substrate 21 of the second substrate 20. Thelight blocking members BML may be formed by applying a light blockingmaterial containing a material for blocking light, and then exposing anddeveloping it. The light blocking members BML may be formed together inone process. A patterned light blocking member BML may partially exposethe second base substrate 21.

Referring to FIG. 7 , the dummy color filter layer CFLd may be formedbetween the light blocking members BML exposing the second basesubstrate 21. Specifically, the dummy color filter layer CFLd mayinclude the first dummy color filter layer CFL1 d, the second dummycolor filter layer CFL2 d, and the third dummy color filter layer CFL3d. The first, second, and third dummy color filter layers CFL1 d, CFL2d, and CFL3 d of the dummy color filter layer CFLd may be formed byapplying a photosensitive organic material containing a color materialof a specific color and then exposing and developing it. The first,second, and third dummy color filter layers CFL1 d, CFL2 d, and CFL3 dmay be formed in the order of the third dummy color filter layer CFL3 d,the first dummy color filter layer CFL1 d, and the second dummy colorfilter layer CFL2 d, but the present disclosure is not limited thereto.

Subsequently, the first capping layer 22 may be formed on a patterneddummy color filter layer CFLd to cover it. The first capping layer 22may be disposed over the entire surface of the second base substrate 21.

Subsequently, referring to FIG. 8 , the second and third partition wallsPTL2 and PTL3 may be formed on the first capping layer 22. Specifically,patterned second and third partition walls PTL2 and PTL3 may be formedon the first capping layer 22. The second and third partition walls PTL2and PTL3 may be formed together in one process. The second and thirdpartition walls PTL2 and PTL3 may be arranged above the light blockingmember BML. The patterned second and third partition walls PTL2 and PTL3may be formed through an exposure and development process. For example,the second and third partition walls PTL2 and PTL3 may include anorganic material which may be a photosensitive organic material. In thiscase, the patterned second and third partition walls PTL2 and PTL3 maybe formed by applying an organic material layer for partition walls andthen exposing and developing it. The organic material layer forpartition walls may be a negative photosensitive material which is curedat a portion irradiated with light, but is not limited thereto.

Referring to FIG. 9 , the second spacer CS2 may be formed on the uppersurface of the partial area of the patterned second partition wall PTL2,and the third spacer CS3 may be formed in the third trench TR3 definedby the outer side surface of the outermost second partition wall PTL2,the inner side surface of the third partition wall PTL3, and the uppersurface of the first capping layer 22. The second and third spacers CS2and CS3 may be formed together in one process. The second and thirdspacers CS2 and CS3 may be formed by applying an organic material layerfor spacers and then exposing and developing it. The organic materiallayer for spacers may be a negative photosensitive material which iscured at a portion irradiated with light, but is not limited thereto.The organic material layer for spacers may be made of a transparentmaterial, but is not limited thereto. The organic material layer forspacers may be made of a semi-transparent material.

Referring to FIG. 10 , dummy wavelength control layers WCL1 d, WCL2 dand TPLd may be formed in the second trenches TR2. The dummy wavelengthcontrol layers WCL1 d, WCL2 d and TPLd may be formed through an inkjetprinting process using an inkjet device IZD. Specifically, the firstdummy wavelength conversion pattern WCL1 d (see also FIG. 11 ) may beformed by ejecting ink IK, which contains a material included in thefirst dummy wavelength conversion pattern WCL1 d, toward a first lighttransmitting area TA1 d (see FIG. 5 ). The ink IK may be injected fromthe area overlapping the first light transmitting area TA1 d into thesecond trench TR2 defined by the second partition wall PTL2. That is,the second partition wall PTL2 may serve to stably guide the ink IK to adesired position to form the first dummy wavelength conversion patternWCL1 d.

Similarly, the second dummy wavelength conversion pattern WCL2 d may beformed by ejecting ink IK, which contains a material included in thesecond dummy wavelength conversion pattern WCL2 d, toward a second lighttransmitting area TA2 d (see FIG. 5 ). The ink IK may be injected fromthe area overlapping the second light transmitting area TA2 d into thesecond trench TR2 defined by the second partition wall PTL2. That is,the second partition wall PTL2 may serve to stably guide the ink IK to adesired position to form the second dummy wavelength conversion patternWCL2 d.

Similarly, the dummy light transmitting layer TPLd may be formed byejecting ink IK, which contains a material included in the dummy lighttransmitting layer TPLd, toward a third light transmitting area TA3 d(see FIG. 5 ). The ink IK may be injected from the area overlapping thethird light transmitting area TA3 d into the second trench TR2 definedby the second partition wall PTL2. That is, the second partition wallPTL2 may serve to stably guide the ink IK to a desired position to formthe dummy light transmitting layer TPLd.

The injection amount of the ink IK may be determined in consideration ofthe surface tension and the volume shrinkage after drying the ink IK.

Referring to FIG. 11 , the second capping layer 23 may be formed on thesecond partition wall PTL2, the third partition wall PTL3, the secondspacer CS2, the third spacer CS3, and the dummy wavelength controllayers WCL1 d, WCL2 d and TPLd. The second capping layer 23 may entirelycover the second partition wall PTL2, the third partition wall PTL3, thesecond spacer CS2, the third spacer CS3, and the dummy wavelengthcontrol layers WCL1 d, WCL2 d and TPLd. FIG. 11 illustrates that thesecond capping layer 23 is formed only in the dummy area DMA and thesealing area SA, but the present disclosure is not limited thereto. Thesecond capping layer 23 may also be formed in the display area DA.

Thereafter, the filling layer 70 (see FIG. 5 ) may be coated on thesecond capping layer 23 and the spacer CS, and the first substrate 10and the second substrate 20 may be bonded to each other. Since the aboveis a well-known fact, a detailed description thereof will be omitted.

According to the method of fabricating the display device 1 inaccordance with an embodiment, the dummy area DMA including the dummypixels DX may be disposed outside the display area DA in order toprevent the display quality of the display device 1 from beingdeteriorated due to the residue phenomenon occurring in a space betweenthe first partition walls PTL1 in the display area DA.

Further, the second substrate 20 included in the display device 1according to an embodiment may have the third trench TR3 disposed in thenon-display area NDA, and the alignment key AK may be disposed in thethird trench TR3. The third spacer CS3 may also be arranged in the thirdtrench TR3 to overlap the alignment key AK. The third spacer CS3 mayinclude a transparent material so that the alignment key AK is easilyvisualized from the front surface of the second substrate 20.

Hereinafter, other embodiments will be described. In the followingembodiments, a description of the same components as those of theabove-described embodiment will be omitted or simplified, anddifferences will be mainly described.

FIG. 12 is a plan view of a display device according to anotherembodiment. FIG. 13 is a cross-sectional view taken along line XIV-XIV′of FIG. 12 .

Referring to FIGS. 12 and 13 , a third partition wall PTL3_1 included ina display device 1_1 according to the present embodiment may have a stemportion PTL31_1 formed along an outer line of the display device 1_1 anda branch portion PTL32_1 protruding inward from the stem portionPTL31_1.

Since the display device 1_1 according to the present embodiment isdifferent from the display device 1 according to an embodiment in thestructure of the third partition wall PTL3_1, a structure of a thirdtrench TR3_1, which is defined by the inner side surface of the thirdpartition wall PTL3_1, the upper surface of the first capping layer 22,and an outer side surface of an outermost second partition wall PTL2_1,may also be formed correspondingly.

In the third trench TR3_1, a third spacer CS3__1 may be disposed. Thethird spacer CS3_1 may cover a part of the outermost second partitionwall PTL2_1, and a part of the stem portion PTL31_1 and the entirebranch portion PTL32_1 of the third partition wall PTL3_1, but is notlimited thereto.

The third partition wall PTL3_1 included in the display device 1_1according to the present embodiment has the stem portion PTL31_1 and thebranch portion PTL32_1 protruding inward from the stem portion PTL31_1,thereby effectively maintaining the height of the third spacer CS3_1.

The display device 1_1 according to the present embodiment may includethe third trench TR3_1 disposed in the non-display area NDA, and havingthe alignment key AK arranged therein. The third spacer CS3_1 may bedisposed in the third trench TR3_1 to overlap the alignment key AK. Thethird spacer CS3_1 may include a transparent material so that thealignment key AK is easily visualized from the front surface of thedisplay device 1_1.

FIG. 14 is a plan view of a display device according to still anotherembodiment. FIG. 15 is a cross-sectional view taken along line XV-XV′ ofFIG. 14 .

Referring to FIGS. 14 and 15 , a display device 1_2 according to thepresent embodiment may include a third partition wall PTL3_2 having aplanar shape of a mesh structure. A third trench TR3_2 included in thedisplay device 1_2 according to the present embodiment may have not onlya third-a trench TR31_2 defined by an outer side surface of an outermostsecond partition wall PTL2_2, the upper surface of the first cappinglayer 22, and the inner side surface of the third partition wall PTL3_2,but also third-b trenches TR32_2 disposed in the third partition wallPTL3_2.

The third-b trenches TR32_2 may be arranged in a lattice shape in thethird partition wall PTL3_2, but are not limited thereto. The third-btrenches TR32_2 may be arranged irregularly. The third-b trench TR32_2may have a rectangular or square shape in a plan view, but is notlimited thereto. The third-b trench TR32_2 may have a circular shape oranother polygonal shape.

The third partition wall PTL3_2 included in the display device 1_2according to the present embodiment has the planar shape of a meshstructure, thereby effectively maintaining the height of a third spacerCS3_2.

The display device 1_2 according to the present embodiment may includethe third-a trench TR31_2 disposed in the non-display area NDA andhaving the alignment key AK arranged therein, and the third-b trenchesTR32_2 disposed in the third partition wall PTL3_2. In the third trenchTR3_2, the third spacer CS3_2 may be disposed to overlap the alignmentkey AK. The third spacer CS3_2 may include a transparent material sothat the alignment key AK is easily visualized from the front surface ofthe display device 1_2.

FIG. 16 is a cross-sectional view of a display device according to stillanother embodiment.

A display device 1_3 according to the present embodiment is differentfrom the display device 1 according to an embodiment in that the lightblocking members BML are omitted. In the fabricating process of thedisplay device 1_3, when the partition walls PTL1, PTL2, and PTL3 areformed, residues of materials forming the partition walls may begenerated in the spaces between the partition walls PTL1, PTL2, andPTL3. In order to prevent the display quality of the display device 1_3from being deteriorated due to generation of the residues of thepartition wall material in the display area DA, the dummy area DMAincluding the dummy pixels DX may be disposed outside the display areaDA. Accordingly, light emission may not be substantially performed inthe dummy area DMA, and the light blocking member and the color filtermay not be disposed therein.

The display device 1_3 according to the present embodiment may include athird trench TR3_3 disposed in the non-display area NDA, and having thealignment key AK arranged therein. In the third trench TR3_3, a thirdspacer CS3_3 may be disposed to overlap the alignment key AK. The thirdspacer CS3_3 may include a transparent material so that the alignmentkey AK is easily visible from the front surface of the display device1_3.

In concluding the detailed description, those skilled in the art willappreciate that many variations and modifications can be made to thepreferred embodiments without substantially departing from theprinciples of the present disclosure. Therefore, the disclosed preferredembodiments of the disclosure are used in a generic and descriptivesense only and not for purposes of limitation.

What is claimed is:
 1. A display device comprising: a first substrate; asecond substrate disposed on the first substrate; first and secondpartition walls disposed on the second substrate, the second partitionwall being disposed outside the first partition wall; a first trenchdisposed between the two first partition walls and having a first width;a second trench disposed between the first and second partition wallsand having a second width greater than the first width; an alignment keydisposed on the second substrate and overlapping the second trench; afirst spacer disposed on the alignment key; and a sealing memberdisposed along an edge between the first substrate and the secondsubstrate without overlapping the alignment key, wherein the firstspacer partially overlaps the first partition wall, the second partitionwall, and the sealing member.
 2. The display device of claim 1, whereinthe display device includes a dummy area and a sealing area, and thealignment key is disposed in the sealing area and disposed inside thesealing member.
 3. The display device of claim 1, wherein the sealingmember does not overlap the first partition wall.
 4. The display deviceof claim 1, wherein a wavelength control pattern is disposed in thefirst trench.
 5. The display device of claim 4, further comprising asecond spacer disposed on a partial area of the first partition wall andnot overlapping the alignment key.
 6. The display device of claim 5,wherein the first spacer and the second spacer are formed by the sameprocess.
 7. The display device of claim 6, wherein the first spacerincludes a transparent material.
 8. The display device of claim 4,wherein the wavelength control pattern includes at least one of awavelength conversion material or a scattering material.
 9. The displaydevice of claim 1, further comprising a filler disposed inside thesealing member between the first substrate and the second substrate. 10.A display device comprising: a first substrate; a second substratedisposed on the first substrate; a sealing member disposed along an edgeof the first substrate between the first substrate and the secondsubstrate; first and second partition walls disposed on the secondsubstrate, the second partition wall being disposed to surround thefirst partition wall; an alignment key disposed between the first andsecond partition walls without overlapping the sealing member; and afirst spacer disposed on the alignment key and partially overlapping thefirst partition wall and the second partition wall, wherein the sealingmember is disposed on the first spacer and the second partition wall.11. The display device of claim 10, further comprising a second spacerdisposed on a partial area of the first partition wall and notoverlapping the alignment key.
 12. The display device of claim 11,wherein the first spacer and the second spacer are formed by the sameprocess.
 13. The display device of claim 12, wherein the first spacerincludes a transparent material.
 14. The display device of claim 10,wherein the sealing member does not overlap the first partition wall.15. The display device of claim 10, further comprising a filler disposedinside the sealing member between the first substrate and the secondsubstrate.
 16. The display device of claim 10, wherein the alignment keyis disposed on the second substrate and disposed inside the sealingmember.